Inhaler Motion Evaluation Via Weighted DP Matching

Patients diagnosed with bronchial asthma or chronic obstructive pulmonary disease (COPD) are required to use inhalers to control their symptoms. However, approximately 70% of the patients use their inhalers incorrectly because of misunderstandings regarding their use or habituation owing to long-term use. Currently, in-person instructions provided by pharmacists or doctors are the only remedy to this problem. Therefore, new evaluation method, which eliminates the input of a doctor or pharmacist, is urgently needed. This study aims to realize automatic evaluation of individual inhaler motion. A new sensing attachment with inertial measurement unit (IMU) is developed for an inhaler device. We propose an evaluation method using data from the sensing attachment, without doctor or pharmacist issued instructions. The proposed evaluation method for inhaler motion is based on a dynamic programming (DP) matching algorithm. Furthermore, the evaluation method is verified via suitable clinical experiments. Based on the experimental results, all clinical data could be classified by the proposed method.